Commercial fast food restaurants that serve meat cooked on a grill depend on being able to cook the meat very quickly in order to maintain a high volume throughput. It is also important that the cooking be accomplished in a manner that can be readily achieved every time, as the customers depend on substantial uniformity of the served product, both over time and among multiple outlets of the same establishment. Moreover, in order to keep costs to a minimum, it is necessary that this cooking be readily accomplished by relatively unskilled operators with a minimum of effort while maintaining the required high degree of repeatability. Simple grill cooking with the operator using a spatula does not generally fill these needs. Yet a device for use with the grill must be portable to allow cooking at any location on the grill, and to permit the device to be cleaned. Such a device must be of simple construction to facilitate fast and effective cleaning.
It is known in the prior art to cook slabs of meat by pressing a heated plate against the slabs, and further to pierce the meat with metallic spikes during cooking. U.S. Pat. No. 2,770,182, to Jensen discloses an electric meat fryer for use with a heated grill. The meat fryer includes a heated plate overlying the grill and having a plurality of holes. A corresponding plurality of spikes, each spike resiliently fastened to an upper structure, passes through the holes in the plate. The heated plate is spring-biased away from the upper structure, which is mounted for movement towards and away from the grill by a rack and pinion mechanism. During cooking, the device is biased downwardly against the meat with sufficient force to overcome the spring-biasing on the plate, and to drive the spikes through the meat and into contact with the grill. Upon raising the device, the spring biased plate expels the meat from the spikes.
While prior art devices such as this are undoubtedly effective in reducing shrinkage and cooking time, they are wholly unsuitable for use in a fast food restaurant. As discussed above, a portable device that is easily removed from the grill for cleaning, and which can be placed over slabs of meat at an arbitrary position on the grill is required. The prior art devices are manifestly unsuited to this application. Also, a device having multiple springs and an elaborate biasing mechanism is complex, making it both expensive and hard to clean.
The type of meat that is typically served in fast food restaurants imposes further requirements. First, the slabs of meat are often frozen prior to cooking, thereby preventing the spikes from passing through the meat immediately. Rather, the spikes must be urged downward as the meat thaws. In order to effect such a gradual penetration with prior art devices, the operator must remain in attendance to gradually push the spikes through the meat. Any attempt to accomplish this at a rate that is greater than that at which the meat thaws to accommodate the spikes can result in a shattering of the frozen slabs. Additionally, certain of the foods served in fast food restaurants are incapable of withstanding much pressure. For example, fish fillets are easily crushed and deformed unless care is taken to regulate the amount of pressure applied thereto. The prior art devices are capable of exerting considerable force on the slabs of meat to be cooked, and it is difficult to apply a pressure that is sufficient to drive the spikes through the slab while at the same time insufficient to crush the slab with the spring-biased plate. If indeed possible, it requires that the operator pay careful attention to the amount of biasing applied to the cooking device in order not to apply excessive pressure.
Accordingly, there has been presented the need in the fast food restaurant industry for a portable self-cleaning device for cooking slabs of meat, often frozen, on a grill without shattering, crushing, or deforming them. Efforts to design such a device have been generally unsuccessful to date.